1 billion users and most of them are actually from outside of the united states. ceo mark zuckerberg announced the milestone. it took the social media giant six years to hit the 500 million user mark and barely two years to double that. but only 166 million out of the billion users are from the united states. >>> and a reminder get ktvu news to go download the ktvu app. click on the live icon and you can watch all of our newscasts live on your mobile device. >> a very happy reunion today between one south bay girl and her puppy. the dog's four day ordeal after a burglary on monday. >> an i'm back here in just a few moments. the fog hasn't gone away. but that doesn't mean a warm up tomorrow. we have a lot of stuff going on in san francisco, we'll be back. >>> new video tonight of a deadly crash in sonoma county. it happened at 8:10 on or that would drive -- in sonoma. it's not clear who was driving the motorcycle and the cause of the crash is still under investigation. >>> four california facilities have received shipments of steroid injections linked to a deadly meningitis outbreak.